Method for producing solid electrolytic capacitor

ABSTRACT

A method for manufacturing large capacitance solid electrolytic capacitors that can be connected direct with semiconductor component, and offer a superior high frequency characteristic. An aluminum foil  3  is made porous in one of the surfaces, a dielectric layer  2  is formed on the porous portion, a through hole  4  is provided in the aluminum foil  3  at a certain specific location. An insulation layer  5  is formed to cover the other surface, viz. non-porous surface, of the aluminum foil  3  and the inner wall surface of through hole  4 , a solid electrolytic layer  6  is provided on the dielectric layer  2 , and a through hole electrode  7  is formed in the through hole  4 , and then a collector layer  8  is formed on the solid electrolytic layer  6 . The insulation layer  5  disposed on aluminum foil  3  is provided with an opening  9  at a certain specific location, and a connection terminal  10  is provided at the opening  9  of insulation layer  5  and the exposed surface of the through hole electrode  7 , respectively.

TECHNICAL FIELD

The present invention relates to a method for manufacturing solidelectrolytic capacitor for use in various kinds of electronic apparatus.

BACKGROUND ART

In line with the recent trends of downsizing and introduction of higherfrequencies among the electronic apparatus, capacitors are requested tobe compact yet to have a larger capacitance, a lower ESR (EquivalentSeries Resistance) and a lower ESL (Equivalent Series Inductance).

As to the technology for increasing capacitance of a solid electrolyticcapacitor (hereinafter referred to as SEC), the U.S. Pat. No. 5,377,073and the Japanese Patent Laid-open No. H11-274002 disclose a technologyof laminating capacitor elements in a chip-type capacitor. Thus theconventional SECs can be increased in the capacitance, and improved inthe ESR.

However, when mounting the conventional SECs on the surface of a circuitboard like semiconductor components, the SECs need the help of externalterminals for connection. This way of connection poses a limitation inthe improvement of ESL. In order to further reduce the ESL, shapes andlength of terminals for electrical connection and the wirings need to bestreamlined. The present invention addresses the above problems, andaims to offer a method for manufacturing large capacitance SECs that canbe connected direct with semiconductor components and implement asuperior high frequency response.

DISCLOSURE OF THE INVENTION

A method for manufacturing SEC in accordance with the present inventioncomprises the steps of forming a porous portion on one of the surfacesof an aluminum foil, forming a dielectric layer on said porous portion,forming a through hole at a certain specific location of said aluminumfoil, forming an insulation layer on said aluminum foil covering theother surface which is opposite to the one having said porous portionand the inner wall surface of said through hole, forming a solidelectrolytic layer on said dielectric layer, forming a through holeelectrode in said through hole, forming a collector layer on said solidelectrolytic layer, forming an opening at a certain specific location ofsaid insulating layer provided on said aluminum foil, and forming aconnection terminal in said opening and on the exposed surface of saidthrough hole electrode. Since the connection terminals provided in theopening of insulation layer and on the exposed surface of through holeelectrode are disposed on a same plane, the SEC can be connected directwith semiconductor component and offers a superior high frequencycharacteristic.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an SEC manufactured in accordance with afirst exemplary embodiment of the present invention.

FIG. 2 is a cross sectional view of an SEC in the first embodiment.

FIG. 3 is a cross sectional magnified view of an SEC, showing the keyportion in the first embodiment.

FIG. 4 is a cross sectional view of aluminum foil of an SEC, showing astate after chamfering in the first embodiment.

FIG. 5 is a cross sectional view of aluminum foil of an SEC, showing astate after an insulation layer was formed covering the non-poroussurface and the inner wall surface of through hole in the firstembodiment.

FIG. 6 is a cross sectional view of aluminum foil of an SEC, showing astate after a solid electrolytic layer was formed on dielectric layer inthe first embodiment.

FIG. 7 is a cross sectional view of an SEC, showing a state after athrough hole electrode was formed in the through hole in the firstembodiment.

FIG. 8 is a cross sectional view of an SEC, showing a state after acollector layer was formed on solid electrolytic layer in the firstembodiment.

FIG. 9 is a cross sectional view of an SEC, showing a state after anopening was formed in the insulation layer in the first embodiment.

FIG. 10 is a cross sectional view of an SEC, showing a state after aconnection terminal was formed in the opening in the first embodiment.

FIG. 11 is a cross sectional view of capacitor elements of an SEC,showing a state after a package was provided in the first embodiment.

FIG. 12 is a cross sectional view of an SEC, showing a state afterexternal terminals were provided on the package, as well as connectionbumps, in the first embodiment.

FIG. 13 is a cross sectional view of an SEC, showing a state after aresist film was provided on the insulation layer in a second exemplaryembodiment.

FIG. 14 is a cross sectional view of an SEC, showing a state of resistfilm after patterning in the second embodiment.

FIG. 15 is a cross sectional view of an SEC, showing a state after athrough hole electrode was formed in the through hole in a thirdexemplary embodiment.

FIG. 16 is a cross sectional view of an SEC, showing a state after asolid electrolytic layer was formed on the dielectric layer in the thirdembodiment.

FIG. 17 is a cross sectional view of an SEC, showing a state after aninsulation layer was formed on the non-porous surface of aluminum foiland an insulation portion was provided in the through hole in a fourthexemplary embodiment.

FIG. 18 is a cross sectional view of an SEC, showing a state after asolid electrolytic layer was formed on the dielectric layer in thefourth embodiment.

FIG. 19 is a cross sectional view of an SEC, showing a state after athrough hole was formed in the insulation portion in the fourthembodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

A solid electrolytic capacitor (SEC) and the method of manufacture inaccordance with exemplary embodiments of the present invention aredescribed referring to the drawings. The drawings are aimed to presentthe concepts, not to exhibit precise dimensions.

Embodiment 1

Reference is made to FIG. 1-FIG. 3, in a sheet-formed capacitor element1, one of the surfaces of an aluminum foil 3 is made porous by etchingor the like process, a dielectric layer 2 is formed on the porousportion, and a through hole 4 is formed in the aluminum foil 3 at acertain specific location. An insulation layer 5 is provided to coverthe other surface, viz. non-porous surface, of the aluminum foil 3 andthe inner wall surface of through hole 4, and a solid electrolytic layer6 is formed on the dielectric layer 2. A through hole electrode 7 isformed in the through hole 4, and then a collector layer 8 is formed onthe solid electrolytic layer 6. Next, the insulation layer 5 on aluminumfoil 3 is provided with an opening 9 at a certain specific location, andthe surface exposed by the opening 9 is provided with a connectionterminal 10. The through hole electrode refers to an electrode formed inthe through hole.

The capacitor element 1 thus structured is provided with a package 11covering the side surfaces and the collector layer 8. A first externalterminal 12, which is electrically connected with the aluminum foil 3,and a second external terminal 13, which is electrically connected withthe collector layer 8, are provided on the package 11, and then aconnection bump 14 is provided on the through hole electrode 7 and theconnection terminal 10, respectively. A finished SEC is thus completed.In the following, a method for manufacturing SEC in the presentinvention is described referring to the drawings FIG. 4 through FIG. 12.

The aluminum foil 3 with dielectric layer 2 is provided by etching oneof the surfaces of an aluminum foil 3 to make it porous, and thenforming a dielectric oxide film thereon through anode oxidization in aelectrolytic solution. And then, the aluminum foil 3 is provided with athrough hole 4 at a certain specific location, as shown in FIG. 4.

The through holes can be formed altogether by means of a wet etchingprocess. Besides the wet etching, a finer through hole of 100 μm orsmaller can be formed at a high precision level by using a laser beammachining, a punching method, a drilling method, an electric dischargemachining, or the like means. The above methods are applicable to anykinds of materials. When forming the through holes by wet etchingprocess, an aluminum foil 3 is etched after the foil is provided at bothsurfaces with resist film having openings at places corresponding to thethrough holes, and then the resist film is removed. If edge of thethrough hole at the surface to be facing to dielectric layer 2 ischamfered by means of wet etching or the like process, it contributes tofurther improve the reliability of an insulation layer, which will beprovided at a later step. Next, by applying an insulating film throughelectrodeposition, an insulation layer 5 is formed to cover the othersurface, viz. non-porous surface, of the aluminum foil 3 and the innerwall surface of through hole 4, as shown in FIG. 5. Although theelectrodeposition provides an even and intense insulation layer, thereis a possibility that the thickness of the layer turns out to beslightly thinner at the edge of through hole 4 facing the dielectriclayer 2. The edge chamfering is effective for eliminating the risk andimplementing a higher insulating reliability. Application of aninsulating resin containing a micro gel of high edge-covering property,carbon particles and titanium oxide particles through electrodepositionis quite advantageous. The micro gel referred to in the present exampleis a polymer added with a polymer substance of particle diameter 10 μmor smaller to increase the viscosity and lower the fluidity; therebyimproving the edge-covering property. However, if a resin mixture ofhigh edge-covering property is electrodeposited onto the inner wallsurface of fine through hole of 100 μm or smaller, the deposited layermay become too thick and clog the through hole. Therefore, it is advisedto split the electrodepostion into two stages; first attaching a thinfilm of a high resistively resin and then an insulating resin which is amixture of a micro gel of high edge-covering property, carbon particlesand titanium oxide particles. By so doing, an insulation layer 5 of lowfailure rate is provided on the inner wall surface of through hole.Then, as shown in FIG. 6, a solid electrolytic layer 6 is formed on thedielectric layer 2. The solid electrolytic layer 6 can be formed througha chemical polymerization or an electrolytic polymerization of a πelectron conjugated polymer such as polypyrrole, polythiophene, and/or acomposite material containing a conducting polymer other than that; orby combining these. Besides the above-described process, it can beformed by applying a suspension of conducting polymer and drying it, andthen conducting an electrolytic polymerization; or, by impregnating itwith manganese nitrate and then heat-decomposing it to generatemanganese dioxide, and then conducting an electrolytic polymerization. Afurther established technology available for forming a solidelectrolytic layer is forming manganese dioxide by heat-decomposingmanganese nitrate. Thus, the productivity and the reliability can beimproved by selecting an appropriate process that provides an intenselayer at an optional thickness.

Next, a process for forming a through hole electrode 7 in the throughhole 4, as shown in FIG. 7, is described. The through hole is filledwith a conducting adhesive substance such as Ag paste, Cu paste, etc.containing conductive particles; and then it is cured to form thethrough hole electrode 7. And then, a collector layer 8 is formed on thesolid electrolytic layer 6, as shown in FIG. 8. The collector layer 8 isformed by using a suspension of carbon particles and a conductingadhesive material containing a silver past as the main ingredient, intoa laminate structure of a carbon layer and a silver paste layer. Thestructure efficiently makes the electrical charges available. Then, asshown in FIG. 9, the insulation layer 5 formed on the other surface ofaluminum foil 3 is provided with an opening 9 at a certain specificlocation, by means of YAG laser or other process such as grinding.Besides the above method, the opening 9 can be formed also by otherprocess; namely, providing a resist portion on the aluminum foil 3before formation of insulation layer 5 at a certain specific place onthe non-porous surface, and forming a collector layer 8 and aninsulation layer 5, and then removing the resist portion. Then, aconnection terminal 10 is formed on the surface exposed through theopening 9 of insulation layer 5, as shown in FIG. 10, using a conductiveadhesive substance, or by an electroplating or electroless plating. Thecapacitor element 1 is covered with an epoxy resin package 11, as shownin FIG. 11, for protecting it from humidity and stress from outside andensuring good electrical insulation and increasing the reliability. Thepackage 11 is provided with a first external terminal 12, which iselectrically connected with the aluminum foil 3, and a second externalterminal 13, which is electrically connected with the collector layer 8,to complete a finished capacitor element 1.

The component of above-described structure functions as it is as an SECof the present invention. However, it is preferred to further provideconnection bumps 14 on the connection terminal 10 and the through holeelectrode 7, in order to raise the reliability in electrical connectionwith a semiconductor component or the like electronic component, and toimprove the electrical performance.

The SECs manufactured in accordance with the above-describedmanufacturing process have the connection terminals 10 and theconnection bumps 14 disposed respectively on a same plane. Thus thepresent invention offers a method for manufacturing SECs that can beconnected direct with semiconductor components, and superior in the highfrequency characteristic.

Embodiment 2

FIG. 13 and FIG. 14 are the drawings used to describe the main processsteps of manufacturing an SEC in accordance with a second exemplaryembodiment of the present invention.

One of the surfaces of an aluminum foil 3 is etched for making itporous, and a dielectric layer 2 is formed on the porous portion. Andthen, a through hole 4 is formed in the aluminum foil 3 at a certainspecific location, and an insulation layer 5 is provided to cover theother surface, viz. non-porous surface, of aluminum foil 3 and the innerwall surface of through hole 4.

So far, the procedure remains the same as in the embodiment 1. Next,when providing a solid electrolytic layer 6 on the dielectric layer 2,if the through hole has a diameter 80 μm or larger the solidelectrolytic layer 6 could form on the other surface, viz. non-poroussurface, of aluminum foil 3.

In order to prevent this to happen, a photo sensitive resin is appliedon the surface of insulation layer 5, as shown in FIG. 13, by usingeither of the methods among an immersion method, a spin coating processand a screen printing method. The photo sensitive resin is cured to forma resist film 15.

Instead, an adhesive organic film may be used for the resist film 15. Inthis case, a film is attached on the surface of insulation layer 5. Andthen, the film is provided with a hole of certain specific dimensions ata location corresponding to the through hole 4, as shown in FIG. 14, bymeans of a photo processing or a mechanical machining. The film is usedas the resist film. A solid electrolytic layer 6 and a through holeelectrode 7 are provided in the same way as in the embodiment 1, andthen the resist film 15 is removed. Thus, no solid electrolytic layer 6is formed on the other surface, viz. non-porous surface, of aluminumfoil 3, and the positive electrode and the negative electrode are surelyseparated. Thereafter, in the same way as in the embodiment 1, acollector layer 8 is formed on the solid electrolytic layer 6, anopening 9 is formed in the insulation layer 5 disposed on the othersurface of aluminum foil 3 at a certain specific location, and aconnection terminal 10 is provided at the opening 9 of insulation layer5 and on the exposed surface of through hole electrode 7, respectively.Thus in an SEC manufactured in accordance with the manufacturing methodof the present embodiment 2, a possible spreading of the solidelectrolytic layer onto the opening 9 of aluminum foil 3 is avoided,since the opening is formed at a later step, and the positive electrodeand the negative electrode are certainly separated to each other.

Embodiment 3

FIG. 15 and FIG. 16 are the drawings used to describe the main processsteps of manufacturing an SEC in accordance with a third exemplaryembodiment of the present invention.

One of the surfaces of an aluminum foil 3 is etched for making itporous, and a dielectric layer 2 is formed on the porous portion. Andthen, a through hole 4 is formed in aluminum foil 3 at a certainspecific location, and an insulation layer 5 is provided to cover theother surface, viz. non-porous surface, of aluminum foil 3 and the innerwall surface of through hole 4.

So far, the procedure remains the same as in the embodiment 1. Next,when providing a solid electrolytic layer 6 on the dielectric layer 2,if the through hole has a diameter 80 μm or larger the solidelectrolytic layer 6 could form on the other surface, viz. non-poroussurface, of aluminum foil 3.

In order to prevent this to happen, a through hole electrode 7 is firstformed in the through hole 4, as shown in FIG. 15.

The through hole electrode 7 is formed by filling a conductive adhesivesubstance such as Ag paste or Cu paste containing conductive particles,and curing it. And then, a solid electrolytic layer 6 is formed on thedielectric layer 2, as shown in FIG. 16. Therefore, no solidelectrolytic layer 6 can be formed on the other surface, viz. non-poroussurface, of aluminum foil 3. And then, a collector layer 8 is formed onthe solid electrolytic layer 6 in the same way as in the embodiment 1,and an opening 9 is formed in the insulation layer 5 covering thesurface of aluminum foil 3 at a certain specific location by means ofYAG laser, or the like process. The opening 9 can be formed instead byproviding a resist portion beforehand on the non-porous surface ofaluminum foil 3 using photo sensitive resin or the like material priorto formation of the insulation layer 5, and removing the resist portionafter collector layer 8 is formed. And then, connection terminal 10 isprovided on the exposed surface at the opening 9 and on the through holeelectrode 7, respectively. Thus in an SEC manufactured in accordancewith the manufacturing method of the present embodiment 2, a possiblespreading of the solid electrolytic layer onto the opening 9 of aluminumfoil 3 is avoided, since the opening is formed at a later step, and thepositive electrode and the negative electrode are certainly separated toeach other.

Embodiment 4

FIG. 17 and FIG. 18 are the drawings used to describe the main processsteps of manufacturing an SEC in accordance with a fourth exemplaryembodiment of the present invention.

One of the surfaces of an aluminum foil 3 is etched for making itporous, and a dielectric layer 2 is formed on the porous portion. Andthen, a first through hole 4 is formed in the aluminum foil 3 at acertain specific location. So far the procedure remains the same as inthe embodiment 1. Next, an insulation layer 5 is formed to cover theother surface, viz. non-porous surface, of aluminum foil 3 and the innerwall surface of through hole 4. And then, a solid electrolytic layer 6is provided on the dielectric layer 2. If the through hole has adiameter 80 μm or larger, the solid electrolytic layer 6 could form onthe other surface, viz. non-porous surface, of aluminum foil 3.

In order to prevent this to happen, an insulation layer 5 is formed onthe other surface, viz. non-porous surface, of aluminum foil 3, and aninsulating portion 16 inside the first through hole, in the first placeas shown in FIG. 17. The insulation layer 5 is formed in the same way asin the embodiment 1. The insulating portion 16 can be provided byelectrodepositing an easy-to-fill insulating resin for several times tofill the through hole, or screen-printing or potting an insulatingresin. And then, as shown in FIG. 18, a solid electrolytic layer 6 isformed on the dielectric layer. And, as shown in FIG. 19, a secondthrough hole 17 is formed inside the insulating portion 16. When theabove procedures are followed, no solid electrolytic layer 6 can beformed on the other surface, viz. non-porous surface, of aluminum foil3.

And then, in the same way as in the embodiment 1, a through holeelectrode 7 is formed in the second through hole 17, a collector layer 8is formed on the solid electrolytic layer 6, and then the insulationlayer 5 disposed on the aluminum foil 3 is provided with an opening 9 ata certain specific place, and a connection terminal 10 is provided atthe opening 9 of insulation layer 5 and on the exposed surface ofthrough hole electrode 7.

Thus in the method of manufacturing SEC in accordance with the presentembodiment 4, the reliability in insulation between the through holeelectrode 7 and the aluminum foil 3 is improved, and a possiblespreading of solid electrolytic material onto the aluminum foil 3 at theopening 9 is prevented, to a sure separation between the positiveelectrode and the negative electrode.

INDUSTRIAL APPLICABILITY

In the method for manufacturing SECs in accordance with the presentinvention, the connection terminals provided at the opening ofinsulation layer and on the exposed surface of through hole electrode,respectively, are disposed on a single flat plane. Thus the presentmethod of manufacture enables to manufacture with ease the largecapacitance SECs that can be connected direct with semiconductorcomponents and provide a superior high frequency characteristic.

1. A method for manufacturing a solid electrolytic capacitor comprising:providing an aluminum foil having first and second surfaces, forming aporous portion on the first surface of said aluminum foil, forming adielectric layer on said porous portion, forming a through hole havingan inner wall surface at a location in said aluminum foil, forming aninsulation layer on said aluminum foil to cover both the second surfacethat is opposite the first surface and the inner wall surface of saidthrough hole, forming a solid electrolytic layer on said dielectriclayer, forming a through hole electrode having an exposed surface insaid through hole, forming a collector layer on said solid electrolyticlayer, forming an opening at a location in said insulation layer locatedon said aluminum foil, and locating a connection terminal at saidopening and on the exposed surface of said through hole electrode. 2.The method for manufacturing a solid electrolytic capacitor recited inclaim 1, wherein said through hole is formed by a process comprisingapplication of a photo-resist on both of said first and second surfaces,and said photo-resist is wet-etched after being patterned.
 3. The methodfor manufacturing a solid electrolytic capacitor recited in claim 1,wherein said through hole is formed by using a method selected from thegroup consisting of a laser beam machining, a punching method, adrilling method and an electric discharge machining.
 4. The method formanufacturing a solid electrolytic capacitor recited in claim 1, whereinsaid dielectric layer is located on said porous portion after an edge ofsaid through hole is chamfered.
 5. The method for manufacturing a solidelectrolytic capacitor recited in claim 1, wherein said insulation layeris formed by electrodeposition.
 6. The method for manufacturing a solidelectrolytic capacitor recited in claim 1, wherein said insulation layercomprises electrodeposition of a first layer of a first insulating resinand electrodeposition of a second layer of a second insulating resinformed by mixing a micro gel, carbon particles and titanium oxideparticles.
 7. A The method for manufacturing a solid electrolyticcapacitor recited in claim 1, wherein said through hole electrode isformed by first filling said through hole with a conducting adhesivesubstance and then curing said adhesive substance.
 8. The method formanufacturing a solid electrolytic capacitor recited in claim 1, whereinsaid opening is formed by using one of a laser beam machining method anda grinding method.
 9. The method for manufacturing a solid electrolyticcapacitor recited in claim 1, wherein said connection terminal is formedwith a conducting adhesive substance.
 10. The method for manufacturing asolid electrolytic capacitor recited in claim 1, wherein said connectionterminal is formed by one of an electroplating and an electrolessplating.
 11. The method for manufacturing a solid electrolytic capacitorrecited in claim 1, wherein said solid electrolytic layer is formed of acomposite material comprising at least one among a π electron conjugatedpolymer and a conducting polymer other than said π electron conjugatedpolymer.
 12. The method for manufacturing a solid electrolytic capacitorrecited in claim 1, wherein said solid electrolyte is a conductingpolymer formed by at least one of a chemical polymerization process andan electrolytic polymerization process.
 13. The method for manufacturinga solid electrolytic capacitor recited in claim 1, wherein said solidelectrolyte is a conducting polymer formed by applying a suspension ofpowdered conducting polymer on said dielectric layer, drying saidapplied polymer, and then electrolytically polymerizing said driedpolymer.
 14. The method for manufacturing a solid electrolytic capacitorrecited in claim 1, wherein said solid electrolyte is manganese dioxideformed by heat-decomposing manganese nitrate.
 15. The method formanufacturing a solid electrolytic capacitor recited in claim 1, whereinsaid solid electrolyte is a conducting polymer formed by electrolyticpolymerization after manganese dioxide is obtained by heat-decompositionof manganese nitrate.
 16. The method for manufacturing a solidelectrolytic capacitor recited in claim 1, wherein said collector layercomprises a carbon particle suspension and a conducting adhesivesubstance.
 17. A method for manufacturing a solid electrolytic capacitorcomprising: providing an aluminum foil having first and second surfaces,forming a porous portion on the first surface of said aluminum foil,forming a dielectric layer on said porous portion, forming a throughhole having an inner wall surface at first location in said aluminumfoil, forming a resist portion at a second location on said aluminumfoil, forming an insulation layer on said aluminum foil to cover boththe second surface that is opposite the first surface and the inner wallsurface of said through hole, forming a solid electrolytic layer on saiddielectric layer, forming a through hole electrode having an exposedsurface in said through hole, forming a collector layer on said solidelectrolytic layer, forming an opening in said insulation layer at saidsecond location in said aluminum foil by peeling said resist portion,and locating a connection terminal at said opening in said insulationlayer and on the exposed surface of said through hole electrode.
 18. Amethod for manufacturing a solid electrolytic capacitor comprising:providing an aluminum foil having first and second surfaces, forming aporous portion on the first surface of said aluminum foil, forming adielectric layer on said porous portion, forming a through hole havingan inner wall surface at a first location in said aluminum foil, formingan insulation layer on said aluminum foil to cover both the secondsurface that is opposite the first surface and the inner wall surface ofsaid through hole, forming a resist film covering an entire surface ofsaid insulation layer, forming a solid electrolytic layer on saiddielectric layer, forming a through hole electrode having an exposedsurface in said through hole, peeling said resist film, forming acollector layer on said solid electrolytic layer, forming an opening insaid insulation layer at a second location in said aluminum foil, andlocating a connection terminal at said opening in said insulation layerand on the exposed surface of said through hole electrode.
 19. Themethod for manufacturing a solid electrolytic capacitor recited in claim18, wherein said resist film comprises one of a photo sensitive resinand an adhesive organic film.
 20. The method for manufacturing a solidelectrolytic capacitor recited in claim 18, wherein said resist film isformed by using a method selected from the group consisting of animmersing method, a spin coating process, a screen printing method and afilm attaching method.
 21. A method for manufacturing a solidelectrolytic capacitor comprising: providing an aluminum foil havingfirst and second surfaces, forming a porous portion on the first surfaceof the surfaces of said aluminum foil, forming a dielectric layer onsaid porous portion, forming a through hole having an inner wall surfaceat a first location in said aluminum foil, forming a resist portion at asecond location on said aluminum foil, forming an insulation layer onsaid aluminum foil to cover both the second surface that is opposite thefirst surface and the inner wall surface of said through hole, forming aresist film covering an entire surface of said insulation layer, forminga solid electrolytic layer on said dielectric layer, forming a throughhole electrode having an exposed surface in said through hole, peelingsaid resist film, forming a collector layer on said solid electrolyticlayer, forming an opening in said insulation layer at a second locationin said aluminum foil by peeling said resist portion, and locating aconnection terminal at said opening in said insulation layer and on theexposed surface of said through hole electrode.
 22. A method formanufacturing a solid electrolytic capacitor comprising: providing analuminum foil having first and second surfaces, forming a porous portionon a first surface of the surfaces of said aluminum foil, forming adielectric layer on said porous portion, forming a through hole havingan inner wall surface at a first location in said aluminum foil, formingan insulation layer on said aluminum foil to cover both the secondsurface that is opposite the first surface and the inner wall surface ofsaid through hole, forming a through hole electrode having an exposedsurface in said through hole, forming a solid electrolytic layer on saiddielectric layer, forming a collector layer on said solid electrolyticlayer, forming an opening in said insulation layer at a second locationin said aluminum foil, and locating a connection terminal at saidopening in said insulation layer and on the exposed surface of saidthrough hole electrode.
 23. The method for manufacturing a solidelectrolytic capacitor recited in claim 22, wherein said opening isformed by locating a resist portion on a non-porous surface of saidaluminum foil prior to formation of said insulation layer, and thenpeeling said resist portion after said collector layer is formed.
 24. Amethod for manufacturing a solid electrolytic capacitor comprising:providing an aluminum foil having first and second surfaces, forming aporous portion on a first surface of the surfaces of said aluminum foil,forming a dielectric layer on said porous portion, forming a firstthrough hole having an inner wall surface at a first location in saidaluminum foil, forming an insulation portion on said aluminum foil tocover the second surface that is opposite the first surface and theinside of said first through hole, forming a solid electrolytic layer onsaid dielectric layer, forming a second through hole in said insulationportion, forming a through hole electrode having an exposed surface insaid second through hole, forming a collector layer on said solidelectrolytic layer, forming an opening at a second location in saidinsulation portion located on said aluminum foil, and locating aconnection terminal at said opening in said insulation layer and on theexposed surface of said through hole electrode.